The present invention generally relates to fabrication methods and resulting structures for semiconductor devices. More specifically, the present invention relates to enhancing drive current and increasing device yield in n-type carbon nanotube field effect transistors (CNT FETs) with scaled contacts using a wetting layer.
In contemporary semiconductor device fabrication processes a large number of semiconductor devices, such as field effect transistors (FETs), are fabricated on a single wafer. In some FET device configurations, carbon nanotubes (CNTs) are incorporated in the FET design. CNTs provide an intrinsically ultra-thin body and exceptional electrical properties (e.g., high drive currents, superior current on/off ratios, and a long mean-free-path for ballistic transport), which makes CNT FETs one of the most promising candidates for the sub-10 nm technology node. CNT FETs, like traditional FETs, include a gate, a source, and a drain. In a CNT FET, carbon nanotubes span lengthwise between source and drain regions such that the ends of each nanotube are in contact with the source or drain. Each of the carbon nanotubes defines a conductive media or “channel” for the CNT FET. Gating of the channel occurs by modulation of the barrier heights of the junctions between the carbon nanotubes and the conductive source/drain regions.